When actuating a device driven by a traction rope, the problem frequently occurs that an actuating path that is as short as possible is intended to provide an adjustment path of the traction rope that is as long as possible. If, in particular, a handle or a rotary handle is used to actuate the traction rope, predetermined adjustment of the device driven by the traction rope is to be achieved for ergonomic actuation without the operator having to change grip. These problems occur, in particular, in the case of a lordosis supporting element driven by a traction rope such as is integrated, for example, in the backrest of a vehicle seat. A lordosis supporting element of this type serves to support the lumbar portion of the driver's spine, for which purpose the lordosis supporting element has a protrusion which is oriented forward toward the driver's back.
To form the protrusion, a lordosis supporting element of this type comprises a flexible support element on which a traction rope acts in such a way that tensile adjustment leads to curvature of the support element. In this case, the curvature becomes more marked as the traction rope is increasingly adjusted. To set the height, a support element of this type can itself be height-adjustable. Alternatively, the protrusion can also be formed as a result of the fact that the flexible support element is followed by a height-adjustable flexural carriage which uses correspondingly shaped metal elements in order locally to bulge the support element forward as it passes behind the support element. In this case, the bulging and height adjustment are carried out in a single step.
Traction rope-driven lordosis supporting elements in a vehicle seat are known, for example, from DE 101 35 473 A1 or DE 103 22 190 B3.